Allow for quote with neither author nor source

layouts/shortcodes/quote.html

@@ -1,5 +1,6 @@
 <blockquote>
   <p>{{ .Inner | markdownify }}</p>
+  {{- if or (.Get "author") (.Get "source") -}}
   <span class="cite"><span>― </span>
     {{- if .Get "author" -}}
     <span>
@@ -10,4 +11,5 @@
       <cite>{{ .Get "source" }}</cite>
       {{- if .Get "url" -}}</a>{{- end -}}
   </span>
+  {{- end -}}
 </blockquote>